Buttonhole-sewing machine



July 3 1928.

G. MULLER nu'r'rounonn .sawmd means July 3, 1928. 7 1,675,508

G. MULLER BUTTONHOLB SEWING MACHINE Filed July 20, 1927 a Sheets-Sheet 2 G. MULLER BUTTONHOLE SEWING MACHINE Filed July 2Q, 1927 3 Sheets-Sheet Patented July 3, 1928.

UNITED STATES GEORG MULLER, F BEILIN-ADLERSHOF, GERMANY.

BUTTONEOLE-SEWING MACHINE.

Application filed Julv 20, 1927, Serial No. 207,218, and in Germany February 25, 1924.

This invention relates to a button-hole sewing machine, in which the fabric is fed forwardly and rearwardly, that is to say, is reciprocated, only in the longitudinal direction of the button-hole slit, and the needle which borders the edges or rims of the'slit is so controlled and moved that when the fabric is fed forward, i. e. moved in the one direction,- it oscillates transversely in such a measure or extent as to effect the bordering at the one side of the slit, and when the fabric is shifted rearwardly the needle borders the other side of the slit, but rior to this second bordering, or, more 1 recisely, when the first bordering operation has been finished, the oscillations of the needle are enlarged to such an-extent that now the barring stitches are made, and the same take place when the second bordering operation has been finished, in that now the barring stitches are made; by the term barring stitches I understand t ose located at the ends of the bordered button-hole and having double the length of the actual bordering stitches.

The gist of the invention resides therein that the driving rods for the swinging lever carrying the needle guide member is connected by a guide-rod with the driving swinging lever, the junction joint'of which is, while the machine is at work, so re-adjusted by means of a cam-disk and of controlling arms co-operating with it that for the production of the first set of barring stitches (after one rim at the slit has been bordered) the extent of the oscillations of the needle is suitably enlarged, and is reduced to its former extent when said barring has been effected, but simultaneously with 40. this re-reduction of the extent of the oscillations of the needle a shifting of such a direction takes lace that the needle oscillates now over t e other rim at the slit in 4 the fabric, this latter moving now in the reverse direction and the other half ofthe button-hole being now bordered. This having been done, the extent of the oscillation of the stitches is a ain enlarged by so much as required for t e other set of barring stitches (at the other end of the button-hole) and finally the extent of the oscillations is again reduced to its former magnitude and another shiftin is eflected so that now another button-ho e can be bordered and finished in the same manner.

rangement and combination of parts in several other positions (Figures 2-5 are purely diagrammatical); Figure 6 is a view corresponding to Fig. 2 and showing the parts in constructive design, Figure 7 is a plan of these parts, and Figures 8-11 show some of the parts of Fig. 6 in other positions (Fig. 8 corresponding to Fig. 2, Fig. 9 to Fig. 3, Fig. 10 to Fig. 4, and Fig. 11 to Fig. 5).

On the drawings, 1 (Figs. 2-6) denotes a pivot supported in the frame of the machine and carrying a bell-crank lever 2, the tree end 3 of which engages a curved rotatlng groove (Fig. 6) of such shape that it is rocked thereby. The other end of said lever is hinged at 4 to a rod 5 hinged in turn at 6 to a thrust-rod 7 hinged again in turn at 8 to another bell-crank lever 11 supported by a pivot 9 and receiving at its free end the needle-guiding member (not shownt}.

In ront of the above-described members is located a cam-disk 12 (shown partly in dotted lines in Figs. 2-5 and in full lines in in Figs. 8-11 and being drawn in these figures to a smaller scale relatively to Figs. 2-5), the periphery of which contacts with a roll 13 held by an arm 15 carried by a shaft 14, to which is afiixed an arm 16, the lower end of which is subjected to the pull of a tensile spring 18 by which the roll 13 is continually held in contact with the disk 12, the cam 31 of which can move the arms 15 and 16 counter to the direction indicated by the arrow I, as in Fig. 2.

The cam disk 12 co-operates also with a two-armed lever 20 carried by a pivot 19 and having at one end a roll 21 which contacts with the peripheral surface of said disk. The other end 22 of the lever 20 bears against an arm 23 hinged at 24 to the arm 16 and subjected to the pull of a tensile spring 27 whereby the roll 21 is continuously held in contact with the disk 12. The levers other set. The arrow a indicates the direction in which the fabric is moved in order to receive the bordering A, and the arrow 6 indicates the direction in which the fabric is moved in order to receive the bordering A. The barring stitches B are made when the bordering stitches A have been made, and the barring stitches B are made when the bordering stitches A have been made.

The needle (not shown) is oscillated by the bell=crank lever 11 continuously as long as the button-hole is moved along below the needle, the needle oscillating transversely to the direction of motion of the fabric with the button-hole, and the extent of the oscillation corresponding to the breadth of the bordering. The bell-crank lever 11 is rocked by the bell-crank lever 2 and the connecting members and 7. Also. the disk 12 rotates continuously, but the members 13, 15, 16 and 23, as well as the members 21, 20 and 22 remain at rest as long as the bordering op eration proceeds, in that none of the cams of the disk 12 acts on any one of the rolls 13 and 21.

Now, it must be borne in mind that the needle must perform two long sets of short oscillations (for the borderings A and A) and two short sets of lon oscillations (for the barring stitches B and B). The positions of the operating parts in the Figs. 2 and 4 are those which they assume when the two long sets of short stitches are made, and the positions of the parts in the Figs. 3 and 5 are those which they assume when the two short sets of long stitches are made. In Fig. 2 the roll 13 has just been engaged by a long cam 31 of the disk 12. There are, by the way, besides said long cam, two short ones 33 and 34. 32 denotes-that portion of the circumferential surface of the disk 12 where thereis no cam. WVhen the members 13, 15, 16, and 23 are acted on by the cam 31, as in Fig. 2, the bell-crank lever 11 oscillates as in this figure, and when the roll 13 runs on the portion 32 of the circumference of the disk 12, as in Fig. 4, the bell-crank lever 11 oscillates as in this figure. On a close examination of the ositions of said bell-crank lever in the two figures (2 and 4) it will be seen that they are different, although the oscillations of the members 2, 5 and 7 are always accurately the same. The difference is caused by the roll 13 contacting in Fig. 2 with the cam 31 and in Fig. 4 with the ordinary circumferential surface of the disk 12.

In Figs. 3 and 5 the oscillations are twice as large as those in Figs. 2 and 4, but their positions are not different, as appears from the bell-crank lever 11. There is, however, this difference between the two figures (3 and 5) that in Fig. 3 the roll 21 of the lever 20 is actuated by the short cam 34 and in Fig. 5 by the short cam. 33. The position of the three cams (31, 33,34) with respect to each other appears from Figs. 8-11 from which is to be seen that the short cam 33 lies at a side of the long cam 31, whereas the other short cam (34) lie's remote.

The oscillations of the bell-crank lever 11 are due, however, not only to the members dealt with in the p recedin columns, but also to a link 26 extending rom the joint 6 to a joint 25 which forms a center for the oscillations of the joint 6 when this is lifted and lowered by the rod 5 and the bell-crank lever 2, and it is due to the oscillations ofthe link 26 around the center 25that the joint 8 of the bell-crank lever 11 moves to and fro, as indicated.

Instead of providing the three cams on a common disk, I prefer to provide them on two disks 29 and 30, Fig. 7, of which 29 is provided with the long cam 31, and 30 with the two short cams-33 and 34.

I claim:

A button-hole sewing .machine of that type in which the fabric is moved to and fro in the longitudinal direction of the slit to be turned into a button-hole by being bordered at its two edges or rims, and in which first one edge or rim is bordered, then the 'barring stitches at one end of the butt0nhole are made, then the other edge or rim is bordered, and finally the barring stitches at the other end of the button-hole are made,

comprising, in combination, a bell-crank 1 lever (11) adapted to actuate the needle guide, a rod (7) rocking this lever, another bell-crank lever (2) moving said rod, means for rocking this bell-crank lever, a cam-disk having a long cam (31) and two short ones (33, 34) two rigidly connected arms (15, 16) rocked by said long cam, a third arm (23) hinged to one (16) of said two arms and extendin in the. direction to the first-mentionediell-crank lever, a link (26) connecting said third arm (23) with the joint be- Ill tween the second bell-crank lever (2) and the rod connecting this lever with the first bell-crank lever, a double-armed lever (20) rocked alternately by said short cams and extendin with its free end below.the end of the said third arm (23), and means for keeping the members actuated by the said cams in contactwith them andwith the disk bearing them, for the purpose set forth.

In testimony whereof I afiix my signature.

GEORG: MULLER. 

